Luminaire cooling means



Feb. 9, 1960 J. G. BARAN LUMINAIRE COOLING MEANS Filed May 23, 1955 LUMINAIRE COOLING MEANS Application'May 23, 1955, Serial No. 510,371

" '7 Claims. (Cl. 251-124 This-invention relates to ceiling constructions, and more particularly to ceiling structures incorporating light trolfers or luminaires and means for cooling the same to thereby reduce the sensible heat load in the room below by minimizing the radiation of heat from the luminaire during warm weather when air'conditioning systems are operating on the cooling cycle.

Luminaires, such as fluorescent lighting devices including inverted trough-like reflectors or housings, are commonly spaced in the ceiling to furnish the desired lighting for the room, being frequently interspersed with modular ceiling panels of acoustical or radiant panel heat transfer ceilings. Where the ceilings are used for heating or cooling, the panels may be carried by spaced, parallel pipes forming a suspended ceiling grid, the pipes, and therefore the panels, being heated or cooled by circulating water or other heat transfer medium through them. Such a panel heating system is shown, for example, in the pending application for patent of Joseph G. Baran, Serial'No. 374,866, filed August 18, 1953, now Patent No. 2,818,235.

Although not limitedto this particular type of suspended ceiling construction, the present invention is especially well suited for such a combined panel heating and cooling system. The luminaires may be arranged between a pair of the parallel pipes of the grid,in place of one or more of the modular ceiling panels which would otherwise appear in such location, being, preferably, fiush with the ceiling panel surface. The heat from the luminaires, when the lights are turned on, is absorbed and carried away by the cooling water circulated in the grid system.

The principal object of the invention is to provide means for abstracting substantial quantities of heat from luminaires of standard construction. A further object is to provide such cooling means without complicating in States Patent any way the installation or removal of the luminaires from the ceiling structure.

The invention will be understood by referenceto the following description taken together with the accompanying drawings of illustrative embodiments of the invention, in which drawings- Fig. l is a perspective view taken from above and showing a luminaire and panel ceiling construction with the present invention associated therewith;

Fig. 2 is a detail view of a portion of the heat-absorbing panel shown in Fig. 1, and

Fig. 3 is an enlarged cross-sectional view of the luminaire and cooling construction showing a somewhat modified form of the invention.

Referring in detail to the illustrative construction shown in Fig. 1, the ceiling structure, only the pertinent parts of which are shown, includes a pair of pipes 1 and 2 suitably supported from the building structure by suitable means not here specifically described and in turn supporting metal ceiling panels 3 which constitute the ceiling visible to those in the room below. The

pipes are suitably connected for the circulation of hot or cool water therethrough, depending upon the season of the year and thus the need for heating or cooling the room below, panels 3 being heated or cooled by conduction from the pipes to radiate heat to objects in i the room or absorb heat by radiation therefrom, as the case may be. Panels 3 are supported and held in engagement with pipes by spring clips 4 which clamp curved flanges 5 of the panels to the pipes, all as more fully shown and described in the pending Baran application above identified.

Luminaire 6, including housing 7 having side walls 8 and a top 9, may be mounted in its position between pipes 1 and 2 by any suitable means. For example, the luminaires may be suspended from the building structure, as by rods 10, or may be supported by pipes 1 and 2 by means of a suitable beam or bracket.

A pair of heat absorbing panels 11 and 12 are arranged adjacent the sides 8 of the housing of the luminaire. These panels are preferably composed of a metal having a high heat conductivity, such as aluminum. It is preferably somewhat curled along one edge, as at 13, in the manner of flange 5 of panel 3, to conform to the curvature of the pipes which engage and provide support for the panels. Two or more openings 14 are provided in each heat absorbing panel to permit passage therethrough of clips 4. Each clip extends around the pipe and presses the curled portion 13 of the panel to the pipe in heatexchanging contact therewith. Where the luminaires are incorporated in ceiling panel heating and cooling systems, as illustrated in Fig. 1, each clip may serve to hold both the heat absorbing panel and the radiant heating or cool- ,ing ceiling panel to the same pipe.

The surfaces of panels 11 and 12 facing the luminaire should have the highest possible heat emissivity coefficient and the panel is preferably at least substantially coextensive with the sides 8 of the luminaire housing. The heat absorbing panels may be installed either before or after installation of the luminaire. The angular position of the panel with reference to the associated pipe may be varied somewhat to accommodate luminaires having differing housing dimensions. It should be noted, however, that it is not necessary that panels 11 and 12 physically engage any part of the housing. Heat radiated from the housing, whose outer surfaces are preferably highly emissive, is absorbed by the cooler heat absorbing panel, and the heat so transferred from the luminaire to the panel is conductive through the metal of the panel to the pipe and thence to the cooling water circulated through the same. With lowered temperatures in the luminaire housing and interior, less heat is radiated into the room from the luminaire with resulting increased comfort to those in the room and reduced load upon the air conditioning system.

The structure illustrated in Fig. 3 is similar to that of Fig. 1, except that heat absorbing panels 11a and 12a are extended to overlie top 9 of the housing as well as sides 8. With this construction the top of the reflector or housing, as well as the sides 8 radiate heat, originating from lighting elements shown schematically at 15, to the heat absorbing surfaces of panels 11a and 12a which latter are continuously cooled by contact with pipes 1 and 2 containing circulating cooling water.

It will be apparent that other means may be employed to hold the panel, whose function it is to absorb heat from the luminaire, against the cooling pipe. Other forms of clamping means may be used, the panel may be rigidly attached to the pipe, or it may be an integral part of the pipe.

The invention provides simple and practical means for absorbing heat from, and thus cooling, the room lighting upon radiation from the external surfaces of the luminaire housing, no special luminaire structure is necessary.

Adaptability of the invention to standard lighting fixtures constitutes an important .feature of the invention,

Invention. is ,claimed asfollows:

1.. Ina, ceiling structure including .a coolant-carrying pipe andfa luminaire, installed adjacent saidpipe, means for. cooling said luminaire comprising a heat-absorbing panel, in, contact engagement with said pipe .and in proximatc unattachedljuxtaposition. with a substantial portion of the exterior of said luminaire.

2..In a ceiling structure includingv a pair of spaced coolant-carrying; parallel pipes extendinggenerally horizontally in said structure and a luminaire. havingametal inverted. trough-like housing installed between'said pipes, means for coolingsaid luminaire. comprising apair of heatrabsorbing panels in contact engagement, respectively, with, said pipes, said panels being arranged inproximate unattached juxtaposition with a. substantial portion of said housing.

3. In av ceiling. structure including a pair of'spaced coolant-carrying parallel pipes extending generally hori- Zontally in said structure and a luminaire having a metal inverted trough-like housing installed between said pipes, means for cooling said luminaire comprising a pair of heat-absorbing panels in contact engagement, respectively, .with saidpipes, each said panel being substantially coextensive with the side of said housingadjacent thereto and arranged in proximateunattached juxtaposed relation therewith.

4. In a ceiling structure including a pair of spaced coolant-carrying parallel pipes extending generally horizontally in said structure and a luminaire having a metal invertedtrough-like housing installed between said pipes, means for cooling said luminaire comprising a pair of heat-absorbing panels in contact engagement, respectively, withsaid pipes, each said panel overlying in proximate unattached relation thereto the side of said housing 7 adjacent said panel and a portion of the top of said housing.

5. In a ceiling structure including a pair of spaced coolant-carrying parallel pipes extending generally horizontally in said structure and a luminaire having a metal inverted troughvlike housing installed between said pipes,

' means for cooling said "luminaire comprising-'f-pair of heat-absorbing panels in contact engagement, respectively, with said pipes, said panels being arranged in proximate unattached juxtaposition with a substantial portion of said housing, and spring clips clamping each said panel to the associated pipe.

6. In a ceiling structure including a pair of spaced coolant-carrying paralleP-pipes extending generally horizontally ingsaid structure and-a luminairehaving a metal inverted trough-like housing installed between said pipes, means for cooling said luminairecomprising a pair-of heat-absorbing panelsarrangedin proximatejuxtaposition with a substantial portion of said housing, each'said panel engaging; one lot said; pipes =alongvan edgejmargin thereof, each said panelhaving an opening therein adjacent said edge marg'in' thereof, and aspring clip embracing a pipe and extending through said opening and clamping said edge margin of said panel to the pipe.

7. A, ceiling; panelcooling; and; lighting system including'apair-of spaced apart. coolant conductingpipes, a luminaire installed between saidpain of-pipes, a ceiling panel arrangedadjacent said luminaire andhaving an integral flange engaging one of said pair of pipes, and a heat-absorbing-panel engaging said one of saidpair of pipes adjacent an edge of -said heat-absorbingpanel and arranged in proximate-.juxtapositionwith a substantial portion of saidluminaire, said heat-absorbing panel having an openingtherein adjacent said edge thereof anda spring clip-embracingsaid one of said pair of pipes and extending through said opening and 'clampingboth said flange of said ceiling panel and said heat-absorbing panel tov said pipe. H

7' References Cited in the file of this patent UNITED STATES PATENTS-r 1,369,008" Christen Feb; 22, 1921 2,317,015 Allen .Apr. 20, 1943 2,662,743 Frenger" Dec. 15, 1953 2,710,336 Jorn June7, 1955 2,713,631- Spinetta Ju1 19, 1955 FOREIGN PATENTS' 1,064,450 France" Dec. 23; 1953 

